Joint Transmit Power and Bandwidth Allocation for Cognitive Satellite Network Based on Bargaining Game Theory

With the rapidly increasing spectrum demand by multimedia applications, the limitation of the spectrum resource restricts the improvement of the performance for communication systems. The cognitive spectrum utilization scenario can solve this problem by sharing the licensed spectrum of primary users (PUs) with secondary users under specific constrains. In this paper, we consider the uplink resource allocation problem in cognitive satellite network, where cognitive satellite users exploit the spectrum allocated to terrestrial networks as PUs. In order to control the interference to the PUs caused by cognitive users and achieve a fair allocation with considerable total capacity, we detailedly investigate the joint transmit power and bandwidth allocation problem with reasonable system model we proposed. We propose combined resource management architecture to improve computational efficiency, and formulate the resource allocation problem as a cooperative bargaining game based on game theory. The near optimal joint resource allocation is derived on dual domain of original problem, and a cooperative resource allocating algorithm is proposed based on subgradient method. From simulation results, several important concluding remarks are obtained as follows: 1) The proposed algorithm has a considerable convergence rate, and distributed computation can further improve computational efficiency; 2) The multi-user and multi-beam diversity can improve total capacity, while interference constrains and the limitation of resource limit the performance boundary; and 3) Compared with existing methods, the proposed algorithm is Pareto optimal, which can achieve a better tradeoff between fairness among users and total capacity of the whole network.